Nearly every well-meaning relative has some advice about foods that will cause an acne break out. Prior to the 1960s, avoidance of certain foods was even recommended in major dermatology textbooks.¹ While many times this type of advice is often written off as old wives' tales with little factual basis, there are some studies that show that what you eat really can impact the health of your skin. Some experts suggest that in actuality it is the assertion that diet has no effect on acne that is ungrounded in fact, but one based on flawed interpretation of research.²

Chocolate

One example of this pertains to a 1969 study in which no link was established between chocolate consumption and an increase in break outs—even in subjects who ate a bittersweet chocolate bar enriched with chocolate liquor and cocoa butter every day for four weeks. Commonly blamed for worsening acne, researchers have been trying to prove its role in worsening acne for decades with varying results. The outcomes of this early research were interpreted to finally disprove any connection between chocolate and acne. However, some researchers have pointed out flaws in this study's design that belie such a definitive interpretation. In fact, the placebo control bar and the enriched bar were comprised of too many different ingredients, thus detracting from the goal of isolating the effects of chocolate.²

In 2010, a small pilot study found enough of a link to launch a complete clinical trial using 100% cocoa. Pure cocoa will be used so researchers can study only the effects of chocolate without interference of other ingredients. The trial, conducted through the University of Miami, aims to study acne patterns in males age 18 to 34 and is expected to be complete in March of 2011.³

Sugar and Starchy Foods

Foods that have a high glycemic index (e.g., candy, processed grains, and starchy vegetables) increase the level of insulin in the body. Higher insulin levels lead to an increase in the growth factor androgen, which plays a role in elevating the body's production of sebum. The role of sebum is to protect the skin and keep it from drying out, but too much can cause oily skin and an environment that increases the incidence of acne.^1,2

Although the studies have their limitations, a growing body of recent evidence seems to indicate foods with a high glycemic index may be a cause of acne (although with a relatively low glycemic index,⁴ chocolate lovers out there can take heart):¹

• Examination of 1300 study participants from Papua, New Guinea and Paraguay showed a complete absence of acne in these diverse non-Westernized populations who consumed only low glycemic diets with no processed foods like cereals, chips, and breads.¹
• Pharmaceutical drugs designed to treat insulin resistance (e.g., metformin and pioglitazone) have been shown to reduce acne in patients with polycystic ovary syndrome (PCOS).¹
• Most of the older studies on diabetic patients taking the drug tolbutamide showed that this insulin-regulating drug improved acne symptoms.² More recent studies demonstrated that tolbutamide reduced acne in PCOS patients as well.¹
• A small randomized clinical trial involving 23 teenage and adult males who followed a controlled diet of low-glycemic foods showed significant reductions in acne symptoms along with increased insulin sensitivity. The researchers also noted weight loss in the study participants following the low-glycemic diet, which may have played a role in acne improvement.¹
• Similarly, in a study of 12 male acne patients fed either a low-glycemic or high-glycemic diet for a week in a research facility, those in the low-glycemic group had improved insulin sensitivity. Conversely, the high-glycemic diet group had significant increases in androgen.¹

Omega-3 Fatty Acids

Although a comprehensive review of studies on diet and acne conducted by medical doctors from major American universities published in 2009 indicate scant research on the role of omega-3 fatty acids and acne, those that exist suggest these fatty acids may reduce inflammation related to acne. The review included an early 1960s study of more than 1000 teens in North Carolina which found acne was less likely in those teens whose diets included greatest amounts of seafood rich in omega-3 fatty acid.¹

For those who don't like seafood, other sources of omega-3 include wild game.¹ Or you may want to try readily available omega-3 supplements. Oral supplementation of Omega-3 was also shown to reduce the incidence of acne in a small 2008 study, as well as improve mood. Given the connection between stress and acne, this omega-3 mood-boosting attribute may also prove to be a significant benefit for acne patients.⁵

Milk

Besides chocolate and fatty acids, milk has long been a topic of study when it comes to diet and acne. Though it can be difficult to research because of the lack of a hormone-free dairy placebo for comparison,⁶ researchers are beginning to understand how hormones in milk may or may not impact acne in teens. Several population studies based on questionnaires have suggested that certain growth factors and precursors to testosterone hormones in milk could be responsible for an increase in acne for teens who consume both milk and other dairy products. The production of androgen is again in play as bovine hormones found in milk are thought to interact with human hormones to synthesize a compound, dihydrotestosterone, that has androgenic properties. However, these studies are severely limited in design, and the link between milk or dairy products and acne tenuous at this time. Additional clinical research is necessary to establish if there is a more definitive association.¹

It's important to remember that there are still many studies yet to be conducted to discover the role diet plays in acne. Combinations of factors like heredity, stress, diet, and environment can influence each individual's experience with acne. A balanced diet is a great way to be sure your body has all of the nutrients necessary for maintaining your good health, including the health of your skin.¹